I keep getting the following codes: UO155, PO321.

I have re-set them a couple times.

UO155 is Lost Communication with Instrument Panel Cluster. Maybe this is because I removed the dash to get the radio out to put in a sat radio input. Maybe I did not plug everything back in securely. On the other hand, the Instrument Panel Cluster (tach, speedo) did not come out when I did this, just the radio and the quick disconnects for the various things on the dash, like the 4x4 selector, lights, ect.

PO321 is Ignition Distributor Engine Speed Input Control Range/Performance.

I have no idea what this means.

Niether code trips the check engine light.

I have done the high idle mod and use it from time to time.

This is a used 2006 Lariat longbed/supercab I bought about a month ago with 25,000 miles on it. Carfax was clean and OASIS showed one thing, a replaced power steering pump.

I actually used it for its intended purpose for the first time over the weekend, towing a 22.5 foot boat (about 5,700 pounds on the trailer) on a surge brake equiped trailer. It towed really well. This was a two hour trip from where I picked it up, a combination of everything from open mountainous highway to city streets to the dirt road my cabin is on.

Backing around the fairly small marina and my driveway was not as bad as I thought it would be (stopped at my place overnight and put the boat in the water the next day). The trailer was "tuned" by its prior owner (my father in law gave use the boat and trailer) at a trailer shop for the boat, this was done to get just about exactly 10% tounge weight and was done by adjusting the overall length of the trailer by extending out the beam that the hitch is mounted on. This means the trailer is longer than you would think because the boat is pretty heavy. I will post a few pics later when I get them off the camera.

This coming weekend will be the first tow of my rockcrawling built Jeep on the car carrier I just bought, I'm looking forward to using the built in trailer brake controller (elec brakes on the car carrier, obviously with the boat trailer the TBC is not usable).

The only problem I had towing was that after I went through some fairly bad potholes at highway speed the ABS light came on. After a stop to fuel up the ABS light was not on after restart. That was a painful trip to the gas station, with $75 for a half tanlk of gas for the boat and $115 to fill the truck.